Generic ADC FOM classes

Based on the generic ADC FOM [1], and the similarities observed between several FOM permutations found in the literature, generic FOM classes are proposed. The use of generic FOM classes enables simultaneous treatment of groups of FOM with similar properties, without necessarily defining exactly how bandwidth/sample rate/power dissipation, etc. was defined.

FOM class definitions

Generic FOM classes are defined in the table below. Both the linear and the logarithmic forms are shown. Scaling coefficients are trivial additions, and have been omitted for readability. Similarly, the linear form figures-of-merit have all been written in their “inverted” form in order to simplify comparison with the most commonly used FOM – the “ISSCC FOM”. For more details on the expressions see [1] and [2].

The list of classes is neither complete nor final, but it captures most of the figures-of-merit found in the literature. Effectively, the classification is based on the unique combination of integer values chosen for the coefficients. In practice, which combinations of -2, -1, 0, 1, and 2 were used. A list of all possible classes would be infinite, due to the infinite number of possible permutations, even if only integer values were to be used for the coefficients. But the magnitude of the coefficients has so far always been chosen as zero or one, and in a few exceptions two (Update: J-class FOM use data-fitted arbitrary coefficeints). For lack of better nomenclature, the classes have been labeled {“A”, “B”, “C”, … }, but suggestions for an improved naming system are welcome.

Linear form

Logarithmic form

Examples of use

Some examples of how these FOM classes have been used in the literature are given below. Again, this list is not exhaustive, but it gives examples of exactly what parameter and coefficient values were used, and also a reference citation. The reference given might not be the original, and if you are aware of older references I will greatly appreciate if you let me know. If you are – or believe you are – the author that originally proposed a particular FOM, it would be nice to hear from you.

It is understood that, by exploring all the specific parameters listed in [1] (and more), a large number FOM permutations can be derived in addition to those in the tables below. Note also that all linear-form expressions are written in their “lower-is-better” form also here, and might therefore be inverted compared to the original citation.